# The Association Between Significant Mitral Regurgitation and Atrial Fibrillation Recurrence Post-Ablation

## TL;DR

This study finds that significant mitral regurgitation is linked to higher recurrence of atrial fibrillation after ablation, using advanced statistical methods.

## Contribution

The novel use of inverse probability treatment weighting reveals a significant association between MR severity and AF recurrence post-ablation.

## Key findings

- Significant MR was independently associated with AF recurrence (HR = 2.11, p = 0.003).
- IPTW analysis showed a robust association (HR = 2.41, p < 0.001).
- AF recurrence occurred in 23.4% of patients over a median 19-month follow-up.

## Abstract

Background: Atrial fibrillation (AF) is a common tachyarrhythmia associated with increased morbidity. AF frequently occurs alongside mitral regurgitation (MR). Although the impact of MR severity on AF is well proven, its effect on AF recurrence post-ablation is unclear and was the focus of our study. Methods: Retrospective single-center cohort of patients who underwent AF catheter ablation from 2014 to 2024. Pre-procedural transthoracic echocardiograms evaluated pre-ablation baseline MR severity. Patients with ‘significant’ MR (defined as moderate–severe or severe MR) were compared to those with ‘non-significant’ MR. Univariate Kaplan–Meier (KM) survival analysis, multivariable Cox proportional hazards models, and inverse probability treatment weighting (IPTW) method were applied to assess the association between baseline MR and AF recurrence post-ablation. Results: Among 444 patients undergoing AF ablation, 28 (6.3%) had ‘significant’ baseline MR. Over median follow-up of 19 months, 104 (23.4%) patients experienced AF recurrence. Univariate and KM survival analyses showed a non-significant trend for increased AF recurrence among patients with ‘significant’ MR. Applying KM analysis on balanced IPTW pseudo-population revealed robust association between ‘significant’ MR and AF recurrence post-ablation (HR = 2.41, 95% CI 1.80–3.22, p < 0.001). Multivariate analysis, performed on IPTW-adjusted pseudo-population, including age, gender, LA diameter, LVEF, and AF type, showed ‘significant’ MR to be independently associated with AF recurrence post-ablation (HR = 2.11, 95% CI 1.43–5.73, p = 0.003). Conclusions: Use of IPTW pseudo-population suggests a significant association between baseline MR severity, regardless of its etiology, and AF recurrence post-ablation. This association should be confirmed by future larger studies.